1. Field of the Invention
The present invention relates to an electronic survey instrument, which operates in accordance with survey mechanism control programs created by an operating system used in a versatile computer such as a personal computer.
2. Related Background Art
A conventional electronic survey instrument is controlled by a CPU and a control program which defines the operation of a CPU. However, the conventional electronic survey instrument can load only a standard program for achieving relatively basic functions, and cannot satisfy all of various requirements which vary, depending on the fields of industries.
Recently, survey instruments which can exchange programs have been developed. For example, in Japanese Laid-Open Patent Application Nos. 2-262005 and 3-245010 describes a survey instrument comprising a single drive which receives a card comprising a memory element. The programs of this known survey instrument can be exchanged by using multiple cards which store various programs.
However, the CPU and program of this survey instrument are specific (special-purpose) ones as in the conventional instrument, and it is difficult for a user to improve a program. For this reason, users cannot individually create and use their own programs.
The conventional survey instrument also suffers from the following problems. In order to exchange a program or to copy surveyed data, the card must be temporarily ejected. Handling non-used cards at, e.g., an outdoor survey site is difficult. Further, when a user erroneously inserts a data storage medium in place of a program storage medium, or vice versa, a non-intended operation may be performed.